BMX rebuilding help please!

Nephew is down for half term and has brought his BMX with him for me to help him rebuild (ie rebuild for him) so I need a bit of help having no experience of BMXs (since I was a kid and had a chrome Raleigh).

On first inspection:

Grips (green) are knackered. He wants ones without the flange as they are not cool apparently.

Stem cap - for some reason has holes in it, I am assuming someone had the cables going down though the cap but there is no longer any brakes.

No rear brake - I tried but he won't have one. Am I being uncool suggesting one?

Chainring - looks shagged. It's a blue anodised on (to match the stem and seat clamp) and has the centre hole and off centre bolt.

BB feels okay

Chain - it's a half link chain, not checked the wear but assuming it's knackered. Doesnt seem to be any way to remove it easily so going to have use a chain breaker.

Rear sprocket and freewheel - it slips badly and the teeth are worn. I've not had a proper look yet but I am wondering if it's just the lock nut it lose but due to the wear I am replacing the sprocket anyway so I assume it's all one unit?

Rear hub bearings - shot.

Rear rim - he claims it keeps getting punctures and halfords had a look and claimed he needs a new rim. Not taken a proper look yet but we'll see.

Rear tyre - seen better days

Pedals - bearings okay but all pins gone so needs some new ones.

He's got a stack of CRC vouchers I gave him and we need to get bits quickly so halfords (have sale on again) seems like a good bet also.

Suggestions/what to look for/how to change stuff would be greatly appreciated!

Just taken the freehub off as it was slipping and it looks like the pawl springs are very weak so I assuming it's a dead hub? can't seem to find any way in to replace them. It is a 9T sprocket direct on the freehub and no make on the hub.

Hate to agree with martinxyz and be part of the throwaway society, but there's soooooo many big bargains to be had out there on brand new old stock BMXes right now, by the time you've fixed all the problems on his old one, you could have bought him a pretty good spec new BMX!

By the time you've spent £80 on a new rear wheel and 9T cog, £25 on a 25T chainwheel, £20 on some pedals, £30 on a rear tyre, £10 on some grips, £15 on a chain etc. you're up to almost £200 on parts alone!

There's some good 2013 complete BMX's out there for £200 right now from the likes of CRC and Winstanleys... Makes you think eh!

Just seen the replies about a new bike...yes would kind of make sense but...

teenager who bought the bike off his mate. Therefore it's the 'best bike in the world' to him. To be fair the frame is actually pretty well made and not a heavy lump like a lot of cheap ones.

+ first time I've seen my nephew in about a year due to family conflict. I always struggle for to buy them things as they grow up so fast so this time I got to send him some CRC vouchers when his gran sent me photos of the bmx he was buying (saw it needed new grips etc). This is the first time he's been allowed to get the train down by himself and we've just spent the day paining the sheep shed, tidying up outside, playing baseball with apples and then spent this evening fixing up his bmx together.

Even if he's only learnt how to fix a puncture then it's been useful but I also get the points for being able to undo every nut and bolt that he and his mates and mates dads couldn't undo

I think I spent £51 + £7 for some ball bearings and £5 for some spokes at the LBS including the vouchers I sent him for his birthday. I paid a bit more for stuff as I've had a lot of work on this week so didn't have time to take a look earlier in the week and CRC and the simply bearings got the stuff to me next day. It soon adds up but the biggest expense was the 25T chainring at £19. I'm not sure the freehub will last that long but I've just ridden it around the house and it's not slipped again yet.

He's just been telling his mates back home on skype and he's already planning his next trip down along with a bike jumble visit so I think that's time and money well spent.